Why on earth
would they think a paint can't event? When I was showing, I saw paints all over the place. I never went past novice, either, but there's no reason at all to think he can't.
This is sort of a backward story, but I used to lease a VERY lazy, overweight Arab named Tiffany (she had a thyroid problem...
). I went to my first (and last) horse trials with her doing baby novice and was carrying a crop because she wasn't the biggest fan of going over jumps. She'd just sort of keep slowing down and eventually stop
I was still a beginner, so I just let her. I heard someone make a comment like "why is she using a crop on an arabian? ugh..." So Tiffany had to prove them wrong by refusing every. single. jump. On cross country AND stadium. This is after she jumped out of the dressage ring. Actually, she didn't jump...she just walked over the rope. Lol it was all in slow mo and I just let her go!
So moral of the story I guess is that every horse is different. Sure, you probably won't get to a four star event on a Belgian, but you never know!
But that doesn't even apply because, like Allison said, there are plenty of paints in eventing!